A conventional display device is disclosed in, for example, PTL 1. A device disclosed in PTL 1 is configured as a head-up display (HUD) device for projecting light showing video onto a windshield of a vehicle to cause a user to visually recognize the video as a virtual image. An HUD device of this kind displays information on a target outside a vehicle while superposing the information on scenery seen through a light transmission member such as a windshield, thereby achieving AR (Augmented Reality).